Two Pakistani intelligence officials, who did not want to be identified because they are not allowed to talk to reporters, said two missiles were fired on a hideout for militants in the Gora Qabristan area of North Waziristan, one of the seven districts of Pakistan's volatile tribal region along the border with Afghanistan.

The officials said the militants belonged to the Haqqani network, a pro-Taliban militant group based in North Waziristan that is accused of planning attacks on the United States and NATO forces inside Afghanistan.

U.S. officials have long pushed their Pakistani counterparts to start an operation against the Haqqani network in North Waziristan, but Pakistani officials have said they were already engaged in many areas fighting against militants.

The United States rarely comments on suspected drone strikes. But it is the only country in the region known to have the ability to launch missiles from drones -- which are controlled remotely.